Traffic controlling system for railroads



Aug. 7, 1934.

R. C. LEAKE TRAFFIC CONTROLLING SYSTEM FOR RAILROADS Filed April 30,1931 FIG. 1.

INVENTOR Richard C. Lea ke,

Patented Aug. 7, 1934 PATENT- OFFIQE TRAFFIC CONTROLLING SYSTEM FORRAILROADS Richard C. Leake, Rochester, Y., assignor to General RailwaySignal Company, Rochester,

Application April 30, 1931, Serial No. 533,934

14 Claims.

This invention relates to traffic controlling systems for railroads, andmore particularly pertains to relay systems for use therewith.

In traflic control systems of the directcontrol type, as disclosed, forexample, in the application or" S. N. Wight, Ser. No. 120,423, filedJuly 3, 1926, a remotely controlled polar-neutral relay is usuallyemployed to govern the operation of the switch and signals at aparticular track location. Similarly, in a traific control system or theselector type, as disclosed, for example, in the application of N. D.Preston et al., Ser. No. 455,304, filed May 24, 1930, a three-positionpolar relay is employed in the stepping circuit at each field locationfor the reception of control impulses at that location.

In accordance with the present invention, it is proposed to provide twoneutral relays so connected in combination as to be responsive tochanges in polarity, which combination may be employed similarly as thepolarized relays above referred to, and other similar practicalapplications of polarized relays. This is accomplished by providinglocal energy for normally energizing the two neutral relays, with theconnections so made that the application of energy by the remote controlcircuit will reduce the current substantially to zero in one or theother of the neutral relays dependent upon the polarity of the appliedpotential.

Other objects, purposesand characteristic features of the presentinvention will be in part obvious from the accompanying drawings and inpart pointed out as the description of the invention progresses. V

In describing the invention in detail, reference will be made to. theaccompanying drawing, in which like referencecharacters havingdistinctive exponents will be employed to designate corresponding partsthroughout the several views, and in which:- v v Fig. 1 illustrates aremote control system for railroad track switches as one embodiment ofthe present invention;

Fig. 1A illustrates, a modified arrangement of the relays employed inthe system of the present invention; and

Fig. 13 illustrates a second modified arrangement of the relays employedin the system of the present invention. 7

With reference to Fig. 1 of the accompanying drawing, a railroad trackswitch TS is indicated as being operated to'normal 'or reverse extremepositions by a switch machine SM which may be of any suitable type, suchfor example, as the switch machine disclosed in the patent to W. K.Howe, Patent No. 1,466,903, dated September 4, 1923.

This switch machine SM is governed from a control oflice through themedium of a control lever L, a polarized control circuit and a relaysystem included within the dotted rectangle designated R. The relaysystem R includes two neutral relays 5 and 6, two local battery sources7 and 8, and the respective contacts of the two neutral relays. Theseneutral relays 5' and 6 are contemplated as being of the tractive typehaving such operating mechanisms as to suitably operate their respectivecontacts to either energized or deenergized conditions in accordancewith the energized or deenergized conditions of the respective relaywindings. However, it is to be understood that any other suitable typeof relay may be employed, such as, for example, a motor type relayhaving rotor and field windings, as distinctive from the tractive type.

Normally the windings of the respective neutral relays 5 and 6 areenergized by the battery sources 7 and 8 in series through a circuitfrom the positive terminal of battery '7, through wires 9 and 10,windings of relay 6, wire 11, to the negative terminal of battery 8,from the positive terminal of battery 8, through wires 12 and 13,windings of relay 5, wire 14, to the negative terminal of battery '7.The direction of the flow of current due to this circuit is indicated bythe arrows within the respective relays. Thus, the contacts of the twoneutral relays 5 and 6 are normally in energized positions opening thecontrol circuits of the switch machine SM.

At the control office, a battery 15 is provided having a center orintermediate tap connected to a line wire 16 extending to the fieldlocation while the positive and negative terminals of this battery arearranged so that positive or negative potential is applied to line wire17, through suitable circuit controlling means illustrated in thisembodiment of the present invention as a three- -position manuallyoperable control lever L.

tors or the like to provide a potential at the field location equal tothe potential provided by the respective batteries 7 and 8.

With the lever L in a non-contacting position as shown, the line wires16 and 17 are deenergized and the neutral relays 5 and 6 are energized,so that the potential drop across points 20 and 21 is substantiallyzero, considering of course that the batteries 7 and 8 have equalinternal resistances and provide equal terminal potentials, andconsidering that the relays 5 and 6 have equal resistances.

Thus, when the lever L is moved to one position or the other so as toapply potential across points 20 and 21 equal to the potential provided.by each of the batteries 7 and 8, current flows through one of the twobranches of the parallel circuit in accordance with the sum of theapplied potential and the potential of the battery within that branchdividedby the resistance of the respective branch while there is nocurrent flow in the opposite branch. In other words, with a particularpolarity appliedthe currents in one branch have the same direction andare additive, while in the other branch, the algebraic sum of thecurrents is substantially zero, thus deenergizing the relay in thatbranch More specifically, let Us assume that the lever L is moved to theright which applies positive potential to the point 20 and negativepotential to the point 21, thereby causing a current to flow from thepositive terminal of battery 15, lever L in a right hand position, wire17 to point 20, wire 10, windings of relay 6, wire 11, battery 8, wire12 to point 21, wire 16, to the mid-point of battery 15. The directionof the current in this branch is indicated by the arrow beneath relay 6.Also, a circuit is closed from point 20, through wire 9, to the positiveterminal of battery 7, from the negative terminal of battery 7, throughwire 14, winding of relay 5, wire 13, to point 21. The poten-- tialapplied to points 20 and 21 by battery 15 would cause a current to fiowfrom that battery through this branch including relay 5 in the directionindicated by the arrow above relay 5, if it were not for battery 7, butthe potential of battery 7 opposes the applied potential. Thus, the

currents in the branch including relay 6, and

battery 8 are additive so that the current is substantially double thenormal current provided in that branch by the batteries 7 and 8; whilethe algebraic sum of the currents in the branch including relay 5 andbattery '7 is substantially zero. With. substantially zero current inthe relay 5, its magnetic flux is reduced to substantially zero so thatits armature falls away or drops. 7 With the neutral relay 5deenergized, its contacts are caused to assume deenergized positions, inwhich the reverse operating circuit of the switch machine is closedfromthe positive terminal of battery 25, through wires 26 and 27 frontcontact 28 of neutral relay 6, back contact 29' of neutral relay 5,reverse operating wire 30, through the operating mechanism of the switchmachine SM to the common return wire 31, thence to the nega ive terminalof battery 25. The switch machine operates the track switch to thereverse position in the usual manner and after completing such operationopens its reverse operating circuit, all as described in the abovementioned Patent If the lever L is moved tot-he left hand position, itis obvious that the polarity applied to the points 20 and 21 isreversed, hence causing the neutral relay 6 to be deenergized while theneutral relay 5 remains energized, thus closing the normal operatingcircuit of the switch machine including the normal operating wire 32 andreturning the track switch TS to its normal position. Such operationwill not be described in detail asit will be understood by analogy tothe above description.

With reference to Fig. 1A of the accompanying drawing, a modified formof the relay system B is illustrated, wherein the local energizingcircuits of the relays 5 and 6 are separate from the remotely controlledcircuits by providing two separate windings on each of these relays.

The lower windings of these relays 5 and 6 are energized from thepositive terminal of battery 50, through wire 51, windings of relay 6wire 52, windings of relay 5*, wire 53, to the negative terminal ofbattery 50. This energizing circuit causescurrent to flow in these lowerwindings as indicated by the arrows 54 and 55. The application ofsuitable potential to the points 20 and 21 causes current to flowthrough the upper windings of these relays so that the magnetic fluxesproduced by the upper and lower windings of one relay are additive,while in the other relay the resultant flux is substantially zero. Inother words, the lower or local windings of these relays may be said tobe connected differentially with respect to each other as compared withtheir negative potential to point 21*, it is obvious that currents willflow in the upper windings of the relays as indicated by arrows 56 and57. Hence, the armature of the relay 5 will drop away, while thearmature of the relay 6 will remain in an energized position.

If on the other hand the polarity applied to the points 20 and 21% isreversed, the direction of current flow in the upper windings isindicated by arrows 58 and 59 thus causing the armature of relay 6 todrop away while the armature of relay 5 will remain energized.

It is to be understood that the potential applied to the upper windingsin series must provide such a current value, in accordance with theratio of turns between the upper and lower windings of each relay, thatthe magnetic flux component resulting from such current in each relaywill substantially equal in value the flux component resulting from thecurrent in the respective lower windings.

With reference to Fig. 1B of the accompanying drawing, a modified formof the relay system B is illustrated, wherein the relays 5 and 6 are.provided with local and remotely controlledwindings as explained forFig. 1A, the only difference being that the local or lower windings ofthese relays are connected in multiple with the local battery source50*, although the local or lower windings of the relays aredifferentially connected with respect to each other as compared to theupper windings. However, the resulting operation of the relays is thesame and may be understood by analogy to the description for Fig. 1A.

Although the present invention has been shown as embodied in the remotecontrol of a railroad track switch, it is to be understood that theprinciples involved may be applied to various other applications wherepolar relays are employed. Also, the specific voltages of the variousbatteries, their internal resistance, the resistance of the variouswindings of the relays involved, as well as the resistances of the linecircuits must all be ascertained and determined. for the particularapplication in practice in accordance with the usual engineeringpractices. Also, although only two circuits have been shown selectedthrough the relays 5 and 6, it is to be understood that four distinctiveselections can be made, three in normal operation and the fourth underthe abnormal condition of failure of the local source or sources. Thethird selection (not shown) can be made through a front contact of relay5 in series with a front contact of relay 6. The fourth selection (notshown) can be made through a back contact of relay 5 in series with aback contact of relay 6.

Having described a trafiic controlling system as embodying the presentinvention, it is desired. to be understood that this form is selected tofacilitate in the disclosure of the invention rather than to limit thenumber of forms which it may assume; and, it is to be further understoodthat various modifications, adaptations and alterations may be appliedto the specific form shown to meet the requirements of practice, withoutin any manner departing from the spirit or scope of the presentinvention except as limited by the appended claims.

Having described my invention, I now claim:-

1. A relay system. comprising, two neutral relays connected in anormally energized series circuit with local sources, and means forapplying potential at two points in said series circuit having the samepotential, whereby one or the other or" said two neutral relays isdeenergized depending upon the polarity of said applied potential.

2. In a relay system, in combination, two neutral relays, a local sourceor" electrical energy, and means connecting said neutral relays to said10- cal source to be controlled thereby, a remote control circuit forthe relays, said remote control circuit being connected to the relays soas to make them responsive to the polarity of potential applied to saidremote control circuit.

3. In a relay system, two neutral relays each having local and linewindings, means energizing said local windings diiIerentially withrespect to each other, means energizing the line windings in series,whereby one or the other of said two relays is deenergized dependingupon the polarity applied to said line windings.

l. In a relay system, two neutral relays each having an armature and twoseparate windings for actuation thereof, means energizing one winding ofeach relay from a local source to cause actuation of said armaturee, andmeans for energizing the others of said windings from a remote source toneutralize the actuation of said armatures by said first mentionedenergized windings.

5. In a relay system, in combination, two neutral relays, means normallyenergizing said neutral relays in a series circuit, and means applyingpotential to said series circuit so as to neutralize said means normallyenergizing said neutral relays with respect to one or the other of saidrelays depending upon the polarity of said applied potential.

6. In a relay system, two neutral relays, means continuously energizingsaid neutral relays differentially with respect to each other, and meansremotely controlled for energizing said neutral relays in series,thereby deenergizing one or the other of said neutral relays dependingupon the polarity of said series energization.

7. In a relay system, two neutral relays each having an armature and twoseparate windings, means for energizing one of the windings of eachrelay from a local source to actuate the armatures, and means forenergizing the others of said windings from a remote source of energy toneutralize the actuation of the armatures by the first mentionedenergized windings.

8. In a relay group, a plurality of neutral relays, a single source ofenergy arranged to position the relays in attracted positions, and acircuit for controlling the relays, means for at will placing energy ofdifferent polarities on the control circuit for at will selectivelyde-energizing the relays in accordance with the polarity of energyapplied to the control circuit.

9. In combination, two neutral relays, and two local sources of energyconnected in a series circuit with sources and relays alternating, andmeans for applying potential of selected polarity to two spaced pointsin said series circuit.

10. In combination, two neutral relays, and two local sources of energyconnected in a series circuit with sources and relays alternating andthe sources arranged cumulatively, and means for applying potential ofselected polarity to two spaced points with a source and a relay betweenthe points in said series circuit.

11. In combination, two neutral relays each having two windings, a localsource of energy connected in a series circuit with one winding of eachrelay, and a series circuit including a remote source of energyconnecting up the other windings of the relays.

12. Two neutral relays, a holding winding on each relay, a local sourceof energy connected to the holding windings in multiple, and a controlwinding on each relay connected in a series circuit so that a givenpolarity of energy placed on the control winding causes one controlwinding only to oppose its holding winding.

13. Two neutral relays, a holding winding on each relay, a local sourceof energy connected to the holding windings in multiple to energize theholding windings in opposite directions, and a control winding on eachrelay connected in a series circuit and means for placing potential ofselected polarity on the series circuit.

14. Two neutral relays, a holding winding on each'relay, a local sourceof energy connected to the holding windings to energize the holdingwindings in opposite directions, and a control winding on each relayconnected in a series circuit and means for placing potential ofselected polarity on the series circuit.

RICHARD C. LEAKE.

